Because I'm not the biggest fan of Oliver Stone's films, it's somewhat faint praise to say that Snowden is his best film since Nixon. Still, it's no coincidence that the restraint and thoughtfulness (relatively speaking) of this film are a welcome change from the amped-up style and broad brushstrokes of some of his other work.
As in Nixon, Stone offers up his take on this material as more of a character study than a polemic. Plenty of time is spent digging into the government practices that Snowden eventually blew the whistle on, but it's framed as information driving his personal growth (from Rand-reading government asset to ambivalent iconoclast) rather than as didactic boo-hiss fodder. In a way, Snowden is really a movie about a man torn between his love for a woman (played by Shailene Woodley) and his duty to his country (represented by a best-in-show Rhys Ifans as a sinister yet paternal CIA administrator). This is a well-worn story, but Stone inflects it with enough digital-age paranoia that it feels fresh.
Snowden eventually shades too far into hagiography at the end, trotting out the laughable cliche of a climactic standing ovation and even giving the real-life Snowden a golden-hued cameo. Joseph Gordon-Levitt's performance would have been better off without the altered voice, which wavers in and out and doesn't sound a whole lot like Snowden anyway. And the film as a whole seems largely uninterested in exploring the spiritual rot that can set in for government actors who are essentially omnipotent in their abilities to gather information on people all over the world. Snowden passes over this opportunity in favor of telling a simpler story, but it wouldn't be an Oliver Stone movie if it didn't occasionally favor bombast over subtlety.
(But seriously, biopic directors, stop putting climactic ovations in your movies.)